振动法水泥稳定碎石基层抗裂级配优化设计研究

Research on Optimal Design of Anti-crack Grading of Cement Stabilized Gravel by Vibration Method

沥青路面出现早期反射裂缝与基层水泥稳定碎石级配组成有关。改良矿料级配可以降低水泥剂量,减少干缩和温缩裂缝数量。振动法利用粗集料嵌挤原则和最大密实度理论寻找骨料间隙率合理极小值下的矿料级配,以粗集料间相互嵌锁,水泥浆包裹细集料来填充骨料空隙,形成骨架密实抗裂结构水泥稳定碎石,并用7 d无侧限抗压强度控制矿料级配组成设计。振动法确定的最大干密度和最佳含水量成型试件与施工现场的振动碾压效果较吻合,且干缩系数和温缩系数较小,具有更优的抗裂性能。

Early reflective cracks or corresponding cracks on asphalt pavement are related to grading composition of cement stabilized gravel. Modification of mineral aggregate grading can reduce cement dosage and reduce number of drying shrinkage cracks and temperature contraction cracks. The vibration method looks for mineral aggregate grading at the reasonable minimum value of aggregate clearance rate by means of the principle of embedded squeeze of coarse aggregate and the biggest compaction theory to fill aggregate clearance with interlocking between coarse aggregates and fine aggregate packed with cement slurry so as to form cement stabilized gravel with compact framework and anti-crack structure, and controls design of miner aggregate grading composition with 7 d unconfined compressive strength. The finished test specimens with the maximum dry density and the optimal water content determined by vibration method coincide the vibration rolling effect on construction site with smaller drying shrinkage coefficient and temperature contraction coefficient and exhibits better anti-crack performance.